The White House’s announcement on Monday that it would call for the declassification of material related to the launch of the Russia investigation was widely and justifiably understood as the latest iteration of a long-standing goal of President Trump: undercutting the legitimacy of the investigation by casting doubt on the motives of those involved in its launch.

Trump’s argument relies on the complexity of the interactions between central figures — FBI agent Peter Strzok, Justice Department official Bruce Ohr, former spy Christopher Steele, etc. — and the implication that their interactions are evidence of an anti-Trump conspiracy. Given how much more attention will probably be paid to these allegations as new material is declassified, we decided to outline what’s known about the genesis of the Russia investigation and about those actors in particular to serve as a guide to what’s known.

Several of the timeline items below are taken from our April overview of the investigation.

2013

January 2013. Energy industry consultant Carter Page meets a man named Victor Podobnyy at a conference in New York and begins sharing with him “basic immaterial information and publicly available research documents” (in Page’s words). Podobnyy was an officer with Russia’s foreign intelligence service and is later charged with being an agent of the Russian government.

March. The FBI interviews lobbyist and consultant Paul Manafort, whose work included advising former Ukrainian president Viktor Yanukovych, who himself had links to Russian President Vladimir Putin. Manafort also spent years advocating on behalf of Russian oligarch Oleg Deripaska.

June. The FBI interviews Carter Page after Podobnyy is recorded by U.S. intelligence officials identifying Carter Page as a possible target for recruitment. “It’s obvious that he wants to earn lots of money,” Podobnyy says of Page.

Aug. 25. In a letter sent to a publisher making the case for his expertise on Russia, Carter Page writes, “Over the past half year, I have had the privilege to serve as an informal advisor to the staff of the Kremlin in preparation for their Presidency of the G-20 Summit next month, where energy issues will be a prominent point on the agenda.”

2014

During this year: The government begins a two-year-long effort to get Deripaska to work with American intelligence officials. That effort brings together Justice Department official Bruce Ohr and former British intelligence officer Christopher Steele, both of whom have experience and expertise in Russia. In 2015, Steele helped set up a meeting between Russian and American officials which Ohr attended.

May.Russian interference. Russians working for a group called the Internet Research Agency begin their efforts to interfere in the election and American politics more broadly.

July. The FBI again interviews Manafort. He later says that this interview is about “offshore consulting activities.”

2015

June 2015. Russian interference. Members of the Internet Research Agency begin buying ads targeting American voters on social media.

June 16. Donald Trump announces his candidacy for the Republican presidential nomination.

July. The FBI opens an investigation into Hillary Clinton’s use of a private email server as secretary of state. One of the agents involved in the investigation is Peter Strzok.

Autumn. The conservative website the Washington Free Beacon hires a firm called Fusion GPS to conduct research on several Republican presidential candidates, including Trump.

Dec. 10. Gen. Michael Flynn, a former senior official in military intelligence, is part of a panel discussion in Moscow for the 10th anniversary of the government-backed media outlet Russia Today, for which he is paid. At a dinner, he sits at a table with Putin.

Officials notice an increase in communication between Flynn and the Russian ambassador to the United States, Sergey Kislyak, following the Russia Today event. Flynn will soon become an adviser to the Trump campaign.

2016

February. The FBI briefs Steele on the rules of being an informant for the bureau, an annual procedure for its sources.

Feb. 25. Strzok and FBI attorney Lisa Page, a subordinate of FBI Deputy Director Andrew McCabe with whom Strzok is involved in an extramarital relationship, discuss the Clinton investigation over text messages. “She might be our next president,” Page says. “The last thing you need us going in there loaded for bear.”

April. Perkins Coie, a law firm working for the Clinton campaign and the DNC, hires Fusion GPS to investigate Trump’s ties to Russia. Fusion at some point employs Nellie Ohr, wife of Justice Department official Bruce Ohr, as a contractor.

April 2. Lisa Page texts Strzok: “So look, you say we text on that phone when we talk about hillary because it can’t be traced, you were just venting bc you feel bad that you’re gone so much but it can’t be helped right now.” She later explains that this is a guide to helping Strzok hide their affair from his wife.

April 6.Russian interference. Hackers allegedly gain access to the Democratic Congressional Campaign Committee network after an employee clicks on a spear-phishing email.

Late June. Steele informs Fusion GPS’s Glenn Simpson that he wants to share what he’s learned with the FBI. Simpson considers it for a few days and then acquiesces.

July. Russian interference. Hackers allegedly access the website of a state board of elections and steal detailed information on 500,000 voters. It’s later reported that systems in Illinois and Arizona were compromised with vast amounts of information stolen. (No election results are alleged to have been affected by the hacks.)

Steele shares a report with the FBI, passed to a Rome-based contact with whom Steele had worked on an FIFA investigation. The agent in Rome passed it on to an agent he knew in the New York’s office’s organized crime division, where it languished.

July 2. FBI interviewers question Clinton for three hours about her use of a private email server.

July 5. FBI Director James B. Comey announces that, following the FBI’s investigation, it would not recommend that Clinton face criminal charges for her use of a private email server. This effectively ends the investigation.

Steele meets in London with the FBI agent with whom he’d worked on the FIFA case. He shares some of what he’s learned.

July 7. Carter Page travels to Moscow to give a lecture. While there, he has a brief conversation with a Russian deputy prime minister named Arkadiy Dvorkovich.

July 8. Carter Page informs the Trump campaign about his trip, writing, “Dvorkovich expressed strong support for Mr. Trump and a desire to work together toward devising better solutions in response to the vast range of current international problems.”

July 14. Russian interference. The Russia-linked hackers allegedly provide instructions to WikiLeaks on how to access the stolen material.

July 19. Dossier report. A Steele report claims that Carter Page met with officials from the Kremlin and fossil-fuel giant Rosneft while he was in Moscow.

July 24. Lisa Page and Strzok discuss U.S. District Court Judge Rudy Contreras’s position on the Foreign Intelligence Surveillance Court.

Strzok texts, “I need to get together with him.” The FISC grants surveillance warrants under the Foreign Intelligence Surveillance Act, one of which would soon be sought by the FBI. Strzok denies discussing any case with Contreras when asked by the Justice Department inspector general.

Late July. Australian government officials, seeing the WikiLeaks materials, inform the FBI about the conversation between Downer and Papadopoulos in May.

July 26. Dossier report. A Steele report documents Russia’s efforts at hacking political adversaries, though the report doesn’t detail the hacking that is alleged above.

July 30. Steele meets with Bruce and Nellie Ohr for breakfast at the Mayflower Hotel in Washington. During this meeting, Steele reportedly tells Ohr that Russian intelligence has Trump “over a barrel.”

Dossier report. A Steele report alleges years of contact between Trump and his associates and Russia.

July 31. The FBI launches a counterintelligence investigation into the Trump campaign.

Strzok texts Lisa Page: “damn this feels momentous. Because this matters. The other one did, too, but that was to ensure we didn’t F something up. This matters because this MATTERS.” The “other one” refers to the Clinton investigation.

Aug. 1. Strzok arrives in London as a first step in the counterintelligence investigation. He meets with Downer.

Early August. CIA Director John Brennan informs the Obama White House about intelligence showing a coordinated effort by Russia to undermine the 2016 election.

Mid-August. Brennan shares his intelligence about Russia’s efforts with Comey.

Aug. 15. Strzok texts Lisa Page: “I want to believe the path you threw out for consideration in [Andrew McCabe]’s office — that there’s no way he gets elected — but I’m afraid we can’t take that risk. It’s like an insurance policy in the unlikely event you die before you’re 40.”

Aug. 19. Manafort leaves Trump’s campaign after a report suggests that he received millions in illicit payments from political actors in Ukraine.

Late summer. Fusion sets up off-the-record meetings between Steele and national security reporters to share some of what had been learned.

Aug. 22. Ohr speaks with Simpson who reportedly shares with Ohr “possible intermediaries” between Russia and the Trump campaign.

September. Steele briefs a State Department official named Jonathan Winer about the contents of the dossier. Winer shares a memo summarizing what he’s learned internally but no action is taken.

Sept. 14. Dossier report. Steele writes a report alleging that the Russians have still more information compromising Clinton, emails that they plan to leak after Russian elections in late September. Emails stolen from John Podesta leak in early October. Another report alleges that Trump had paid bribes for business deals in St. Petersburg.

Mid-September. Strzok first sees parts of the dossier, passed to the FBI by Ohr. A few days later, Comey is briefed on the material. By this point, a memo from Democrats on the House Intelligence Committee indicates, “the FBI had already opened sub-inquiries into . . . individuals linked to the Trump campaign.” That probably includes Papadopoulos and Carter Page as well as Flynn and Manafort.

At some point in this time frame, Ohr and Steele discuss the dossier. Ohr later tells FBI investigators that Steele told him he was “desperate that Donald Trump not get elected and was passionate about him not, being president.”

Early autumn. Steele meets with the former head of MI6, Richard Dearlove, who recommends that the information uncovered be provided to the UK government, which could then inform the Americans.

Sept. 23. Yahoo News, apparently after interviews with Steele, reports that Page may have met with officials from Rosneft and the Kremlin.

Ohr and Steele meet for breakfast.

Sept. 26. In an interview with The Post, Carter Page separates publicly from the Trump campaign.

As part of an investigation into possible crimes by former New York representative Anthony Weiner, FBI agents seize one of Weiner’s laptops. On it are emails backed up be Weiner’s wife, Huma Abedin, a top adviser to the Clinton campaign.

Sept. 29. The FBI’s New York field office informs the team in Washington investigating Clinton’s email server that the messages on Weiner’s laptop include some from a BlackBerry account, which the FBI hadn’t obtained.

October. The FBI reaches a deal with Steele to pay him to continue his work investigating ties between the Trump team and Russia. Steele withdraws from the arrangement later in the month after a New York Times story indicates that the FBI saw no link between Trump and Russia.

Oct. 3. Steele again briefs an FBI contact, this time at the bureau’s office in Rome and at the bureau’s request.

Oct. 3 and 4. McCabe and other officials discuss the Weiner laptop, among other things, in meetings.

Oct. 7. The director of national intelligence and head of the Homeland Security Department release a joint statement accusing Russia of attempting to interfere in the election. This statement is quickly buried after The Post publishes the “Access Hollywood” tape.

Oct. 12. Dossier report. A Steele report alleges that more information stolen by Russia was yet to come.

Oct. 18. Steele and Ohr speak on Skype, apparently about Deripaska.

Dossier report. Steele writes a report linking Trump’s personal attorney Michael Cohen to a coordinated effort to interfere in the election and linking Carter Page to a business deal with Rosneft.

Oct. 19. Steele and Ohr speak again.

Oct. 19 and 20.Dossier report. Reports from Steele allege that Cohen traveled to Prague to meet with Russian agents. It’s alleged that he stepped in to guide the relationship after Manafort was fired.

Oct. 21. The FBI is granted a FISA warrant to surveil Carter Page, identified in the warrant application as an agent of the Russian government. The application includes information from Steele’s dossier and a reference to the Yahoo article.

The FBI’s New York field office inquires about the Weiner laptop.

Oct. 27. Comey is told about the newly discovered emails.

Oct. 28. Comey reveals to Congress that Clinton emails were found on the Weiner laptop. The news quickly leaks. The letter was drafted, in part, by Strzok. He changed the language in the letter from describing Clinton’s actions as “grossly negligent” to “extremely careless.”

Former New York mayor Rudolph W. Giuliani, responding to the Comey report, says in a radio interview that “there’s a kind of revolution going on inside the F.B.I. about the original conclusion [about Clinton] being completely unjustified, and almost a slap in the face of the F.B.I.’s integrity.” His source for this, he says, includes “a few active agents who obviously don’t want to identify themselves.” He later walks this back.

Oct. 30. Then-Senate Minority Leader Harry M. Reid sends a letter to Comey alleging the existence of “explosive information about close ties and coordination between Donald Trump, his top advisors, and the Russian government” and requests it be made public.

Late October. The relationship between Perkins Coie and Fusion GPS ends.

Oct. 31. Mother Jones reports on the existence of the Steele dossier after speaking with Steele.

NBC News reports that the FBI is investigating Manafort’s ties to Russia.

Nov. 1. The FBI terminates its relationship with Steele after the Mother Jones article makes clear that he’s been speaking with reporters.

Nov. 6. Comey publicly clears Clinton after a review of the Weiner laptop emails. Lisa Page and Strzok had exchanged text messages discussing whether a public statement made sense.

Nov. 8. Trump wins the presidency.

Nov. 21. Ohr reportedly meets with Strzok and Lisa Page. It appears to concern the ongoing Russia probe and includes discussion of continuing to use Steele as a source.

Dec. 9 or 10. Steele recommends that Simpson discuss the origination of the dossier with Ohr. They meet over coffee and discuss. Simpson gave Ohr a thumb drive which Ohr later testified he didn’t review.

Dec. 13. Ohr and Steele speak.

Dossier report. A Steele report alleges that Cohen’s trip to Prague was meant to tie up loose ends with the Russian interference effort, including paying off hackers.

Dec. 20. Strzok texts Lisa Page and informs her that a colleague “met with [Ohr] and got more stuff today,” presumably a reference to the thumb drive.

2017

January 2017. The Carter Page surveillance warrant is renewed. It includes more than a dozen pages of material added after the first application.

Jan. 6. Trump is informed about the existence of the dossier during a meeting at Trump Tower.

With the material made public, Strzok and Lisa Page discussed using it as a pretext to launch interviews about the allegations.

April. The Carter Page surveillance warrant is renewed. It again includes additional material.

May 9. Comey is fired as director of the FBI.

May 17. Deputy Attorney General Rod J. Rosenstein appoints former FBI director Robert S. Mueller III as special counsel to investigate Russian interference efforts in the 2016 election and any overlap with the Trump campaign. Strzok and Lisa Page are assigned to Mueller’s team.

May 18. After the Mueller appointment, Strzok texts Lisa Page about possibly working for the special counsel. “For me, and this case, I personally have a sense of unfinished business,” he wrote. “I unleashed it with [the Clinton investigation]. Now I need to fix it and finish it.” He adds, “you and I both know the odds are nothing. If I thought it was likely I’d be there no question. I hesitate in part because of my gut sense and concern there’s no big there there.”

June. The Carter Page surveillance warrant is renewed. By now, the application more than 30 pages longer than its original iteration. (The third section is mostly the Steele-provided information; Sections IV through the conclusion are mostly redacted.) This is the final renewal of the warrant.

(Philip Bump/The Washington Post)

July. Lisa Page leaves the Mueller team.

August. Strzok is removed from Mueller’s team shortly after his anti-Trump text messages with Lisa Page come to light.